Turbine component

ABSTRACT

A turbine component is disclosed. The turbine component includes an outer shroud and an inner shroud having a first hook region extending over a first portion of the outer shroud and a second hook region extending over a second portion of the outer shroud. A first hook gap, a second hook gap, a first radial gap, and a second radial gap are arranged and disposed to permit the inner shroud to deflect from the outer shroud under thermal loading. Additionally or alternatively, the inner shroud includes ceramic matrix composite fibers having a thermal conductivity of less than 200 W/m·k and greater than 10 W/m·k.

FIELD OF THE INVENTION

The present invention is directed to turbine components. Moreparticularly, the present invention is directed to turbine componentshaving an inner shroud and an outer shroud.

BACKGROUND OF THE INVENTION

Higher temperature and pressure operation of turbine components inturbine engines and power generation systems permit improved efficiencyand operation in new configurations. Selecting materials capable ofoperating at such higher temperatures and pressures is difficult. Suchmaterials can be cost prohibitive, difficult to produce, or difficult tofabricate. In addition, use of such different materials can requiremodification to cooling mechanisms, which can produce othercomplications.

In general, using less material for similar or better operation isdesirable. Using less material decreases weight, decreases costsassociated with manufacturing, decreases material costs, and providesseveral other advantages. However, using less material can createcomplicated geometric requirements and/or can produce undesirable forcesnot previously generated, such as stress. In addition, as is the casefor using different materials, using less materials can requirecomplicated and/or expensive modifications to cooling mechanisms, whichcan produce other complications.

Thus, there is an ongoing need to produce materials that are capable ofwithstanding higher temperature and pressures, that are capable of beingapplied in lower amounts/weights, are capable of operation withoutproducing undesirable forces, and are capable of use in operationalconditions without employing complicated and/or expensive coolingmechanisms.

A turbine component that shows one or more improvements in comparison tothe prior art would be desirable in the art.

BRIEF DESCRIPTION OF THE INVENTION

In an embodiment, a turbine component includes an outer shroud and aninner shroud having a first hook region extending over a first portionof the outer shroud and a second hook region extending over a secondportion of the outer shroud. The first hook region and the first portiondefine a first hook gap and the second hook region and the secondportion define a second hook gap. A first radial gap extends between thefirst hook region opposite the first hook gap and the outer shroud and asecond radial gap extends between the second hook region opposite thesecond hook gap and the outer shroud. The first hook gap, the secondhook gap, the first radial gap, and the second radial gap are arrangedand disposed to permit the inner shroud to deflect from the outer shroudunder thermal loading.

In another embodiment, a turbine component includes an outer shroud andan inner shroud having a first hook region extending over a firstportion of the outer shroud and a second hook region extending over asecond portion of the outer shroud. The inner shroud includes ceramicmatrix composite fibers having a thermal conductivity of less than 200W/m·k and greater than 10 W/m·k.

In another embodiment, a turbine component includes an outer shroud andan inner shroud having a first hook region extending over a firstportion of the outer shroud and a second hook region extending over asecond portion of the outer shroud. The first hook region and the firstportion define a first hook gap and the second hook region and thesecond portion define a second hook gap, the first hook gap and thesecond hook gap being arranged and disposed to permit the inner shroudto deflect from the outer shroud under thermal loading. The inner shroudincludes ceramic matrix composite fibers having a thermal conductivityof less than 200 W/m·k and greater than 10 W/m·k.

Other features and advantages of the present invention will be apparentfrom the following more detailed description, taken in conjunction withthe accompanying drawings which illustrate, by way of example, theprinciples of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an embodiment of a component having aninner shroud and an outer shroud, according to the disclosure.

Wherever possible, the same reference numbers will be used throughoutthe drawings to represent the same parts.

DETAILED DESCRIPTION OF THE INVENTION

Provided is a turbine component. Embodiments of the present disclosure,for example, in comparison to concepts failing to include one or more ofthe features disclosed herein are capable of simpler repair orreplacement, are capable of withstanding higher temperature andpressures, are capable of being applied in lower amounts/weights, arecapable of operation without producing undesirable forces, are capableof use in operational conditions without employing complicated and/orexpensive cooling mechanisms, and/or are capable of mechanical loadingto reduce leakage, thereby enhancing engine operational efficiencies.

FIG. 1 shows an embodiment of a turbine component 100, for example,capable of being used in a power generation system, a turbine engine, orboth. The turbine component 100 includes an outer shroud 101 and aninner shroud 103 having a first hook region 105 extending over a firstportion 109 of the outer shroud 101, and a second hook region 107extending over a second portion 111 of the outer shroud 101. The firsthook region 105 and the first portion 109 define a first hook gap 113and the second hook region 107 and the second portion 111 define asecond hook gap 115. A first radial gap 114 extends between the firsthook region 105 opposite the first hook gap 113 and the outer shroud 101and a second radial gap 116 extends between the second hook region 107opposite the second hook gap 115 and the outer shroud 101. The firsthook gap 113, the second hook gap 115, the first radial gap 114, and thesecond radial gap 116 are arranged and disposed to permit the innershroud 103 to deflect from the outer shroud 101 under thermal loading.

The first hook gap 113, the second hook gap 115, the first radial gap114, and the second radial gap 116 are any suitable geometry permittingdeflection to reduce or eliminate stress during operational use of theturbine component 100. For example, in one embodiment, a suitablegeometry includes are cuboid channels extending above the inner shroud103. Although the term “hook” is used and FIG. 1 shows a first curvedportion 102, a first planar portion 104 proximal to the first curvedportion 102, a second curved portion 106 proximal to the first planarportion 104, and a second planar portion 108 proximal to the secondcurved portion 106, with the second planar portion 108 extendingsubstantially parallel to the inner shroud and a hot gas path 119, itshall be understood that an angled, arching, curling, curvilinear, orother arrangement that extends into at least three separate planes shallbe considered within the term “hook.” Other suitable geometries include,but are not limited to, a rectangular prism, a slot, a portion of acylinder (such as, a semi-cylinder), an arch with a planar orsubstantially planar border connecting ends of the arch, or any othergeometry providing deflection.

The first hook region 105, the first radial gap 114, and the firstportion 109 are proximal to a leading edge 127 in comparison to atrailing edge 129. The second hook region 107, the second radial gap116, and the second portion 111 are proximal to the trailing edge 129 incomparison to the leading edge 127. The first hook region 105 and thesecond hook region 107 adjustably secure the inner shroud 103 to theouter shroud 101. In one embodiment, the inner shroud 103 and the outershroud 101 are capable of being secured together without bolting byrelying on the first hook region 105 extending over the first portion109 of the outer shroud 101, and the second hook region 107 extendingover the second portion 111 of the outer shroud 101. Any other suitableforce-providing mechanisms are capable of being used to further securethe outer shroud 101 and the inner shroud 103, as well as additionalinner shrouds in embodiments with a plurality of the inner shrouds 103.

In one embodiment, the arrangement of the outer shroud 101 and the innershroud 103, in conjunction with the selected materials, permitsselective removal, repair, and/or replacement of the inner shroud 103from the outer shroud 101. For example, in one embodiment, the innershroud 103 and the outer shroud 101 do not bind under suitableoperational conditions of the turbine component 100. As used herein, theterm “bind” refers to local yielding or deformation of the outer shroud101, for example, above the second planar portion 108. Suitableoperational conditions include, but are not limited to, from about 1200°F. to above 3200° F. (about 650° C. to above 1760° C.).

The inner shroud 103 and the outer shroud 101 include any suitablematerials capable of use within the operational conditions of the powergeneration system, the turbine engine, or any other system utilizing theturbine component 100. In one embodiment, the outer shroud 101 includesa metal or metallic material, such as, a nickel-based alloy or stainlesssteel. In one embodiment, the inner shroud 103 includes a ceramic matrixcomposite. As used herein, the term “ceramic matrix composite” includes,but is not limited to, carbon-fiber-reinforced carbon (C/C),carbon-fiber-reinforced silicon carbide (C/SiC),silicon-carbide-fiber-reinforced silicon carbide (SiC/SiC), andsilicon-carbide-fiber-reinforced oxide matrix composite. In oneembodiment, the ceramic matrix composite material has increasedelongation, fracture toughness, thermal shock, dynamical loadcapability, and anisotropic properties as compared to a monolithicceramic structure. One suitable ceramic matrix composite includes a Si—Cfiber and a SiC-matrix, for example, with the Si—C fiber at aconcentration, by volume, in the ceramic matrix composite of at leastabout 20%, for example, at least about 23%, at least about 28%, at leastabout 30%, between about 23% and about 32%, or any suitable combination,subcombination, range, or sub-range therein.

The materials for the inner shroud 103 are selected to provide a selectrange of thermal conductivity for the turbine component 100. In oneembodiment, the thermal conductivity of the inner shroud 103 and/or thematerial for the inner shroud 103 is less than 200 W/m·k, less than 150W/m·k, less than 140 W/m·k, less than 130 W/m·k, or any suitablecombination, sub-combination, range, or sub-range therein. Additionallyor alternatively, in one embodiment, the thermal conductivity of theinner shroud 103 and/or the material for the inner shroud 103 is greaterthan 10 W/m·k, less than 50 W/m·k, greater than 100 W/m·k, less than 110W/m·k, or any suitable combination, sub-combination, range, or sub-rangetherein. In one embodiment, the thermal conductivity is 120 W/m·k.

The inner shroud 103 and/or the outer shroud 101 include any othersuitable features that do not adversely affect deflection under thermalloading. For example, in one embodiment, outer shroud 101 includes aninternal cavity 117, permitting the flow of a fluid (for example, air orcompressed air). The internal cavity 117 is capable of being sealed, forexample, by spline seals on circumferential faces of the turbinecomponent 100 as well as compliant seals on the leading edge 127 and/oron the trailing edge 129. In one embodiment, the internal cavity 117 ispressurized, for example, to or greater than the operational pressureand/or the pressure of the hot gas path 119 that traverses along thedistal portion of the inner shroud 103 relative to the outer shroud 101.In one embodiment, a transverse gap 121 extends parallel, substantiallyparallel, or tangential between the inner shroud 103 and the outershroud 101 from the first hook region 105 to the second hook region 107and permits heat to be transferred to the outer shroud 101 from theinner shroud 103. In another embodiment, an impingement plate 123 ispositioned between the inner shroud 103 and the outer shroud 101. Theimpingement plate 123 includes material identical, similar, or differentfrom the inner shroud 103 and provides cooling by transferring heat tothe internal cavity 117.

The inner shroud 103 includes any suitable features to respond to theoperational parameters, such as temperature and pressure, resulting frombeing positioned to be contacted by the hot gasses within the hot gaspath 119. For example, in one embodiment, the inner shroud 103 includesan environmental barrier coating 125 positioned on a portion or allsurfaces of the inner shroud 103 positioned to be contacted with the hotgasses in the hot gas path 119. The environmental barrier coating 125 isany suitable coating capable of operation in the hot gas path 119. Toaccommodate blade tip clearance, in one embodiment, an abradable rubcoat (not shown) is included on the inner shroud 103 within the hot gaspath 119. Suitable materials for the environmental barrier coating 125and/or the abradable rub coat include, but are not limited to, bariumstrontium alumino silicate, mullite, yttria-stabilized zirconia, yttriamono and disilicates, yterbium mono and disilicates, and combinationsthereof.

While the invention has been described with reference to one or moreembodiment, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiment disclosed as the best modecontemplated for carrying out this invention, but that the inventionwill include all embodiments falling within the scope of the appendedclaims.

What is claimed is:
 1. A turbine component, comprising: an outer shroud;and an inner shroud having a first hook region extending over a firstportion of the outer shroud and a second hook region extending over asecond portion of the outer shroud; wherein the first hook region andthe first portion define a first hook gap and the second hook region andthe second portion define a second hook gap; wherein a first radial gapextends between the first hook region opposite the first hook gap andthe outer shroud and a second radial gap extends between the second hookregion opposite the second hook gap and the outer shroud; wherein thefirst hook gap, the second hook gap, the first radial gap, and thesecond radial gap are arranged and disposed to permit the inner shroudto deflect from the outer shroud under thermal loading.
 2. The turbinecomponent of claim 1, wherein the inner shroud includes a ceramic matrixcomposite material.
 3. The turbine component of claim 2, wherein theceramic matrix composite material includes a Si—C fiber and aSiC-matrix.
 4. The turbine component of claim 3, wherein the Si—C fiberis at a concentration, by volume, in the ceramic matrix composite of atleast 20%.
 5. The turbine component of claim 1, wherein the outer shroudincludes a metal or metallic material.
 6. The turbine component of claim1, wherein the inner shroud has a thermal conductivity of less than 200W/m·k.
 7. The turbine component of claim 1, wherein the inner shroud hasa thermal conductivity of greater than 10 W/m·k.
 8. The turbinecomponent of claim 1, wherein the inner shroud has a thermalconductivity of about 120 W/m·k.
 9. The turbine component of claim 1,wherein the inner shroud and the outer shroud do not bind duringoperation of the turbine component.
 10. The turbine component of claim1, further comprising an impingement plate positioned between the innershroud and the outer shroud.
 11. The turbine component of claim 10,wherein the impingement plate includes a metal.
 12. The turbinecomponent of claim 1, wherein the outer shroud includes an internalcavity.
 13. The turbine component of claim 12, wherein the internalcavity is pressurized.
 14. The turbine component of claim 13, whereinthe internal cavity is pressurized to a pressure equal to or greaterthan the hot gas path pressure.
 15. The turbine component of claim 1,further comprising a transverse gap extending parallel to at least aportion of the inner shroud between the first hook region and the secondhook region.
 16. The turbine component of claim 1, further comprising anadditional inner shroud positioned abutting the inner shroud andextending over the first portion of the outer shroud and the secondportion of the outer shroud.
 17. The turbine component of claim 1,further comprising an environmental barrier coating positioned on atleast a portion of the inner shroud to be contacted by the hot gas path.18. The turbine component of claim 17, wherein the environmental barriercoating is an abradable rub coat.
 19. A turbine component, comprising:an outer shroud; and an inner shroud having a first hook regionextending over a first portion of the outer shroud and a second hookregion extending over a second portion of the outer shroud; wherein theinner shroud includes ceramic matrix composite fibers having a thermalconductivity of less than 200 W/m·k and greater than 10 W/m·k.
 20. Aturbine component, comprising: an outer shroud; and an inner shroudhaving a first hook region extending over a first portion of the outershroud and a second hook region extending over a second portion of theouter shroud; wherein the first hook region and the first portion definea first hook gap and the second hook region and the second portiondefine a second hook gap, the first hook gap and the second hook gapbeing arranged and disposed to permit the inner shroud to deflect fromthe outer shroud under thermal loading; wherein the inner shroudincludes ceramic matrix composite fibers having a thermal conductivityof less than 200 W/m·k and greater than 10 W/m·k.